A liquid crystal display panel has heretofore been manufactured by applying an inorganic or organic sealing agent in the form of a liquid or film to a sealing area on a sheet of glass defining a substrate for the panel, placing another substrate thereon, and heating the whole to solidify the sealing agent. It has, however, been necessary to inject a liquid crystal through a hole in the substrate after solidification of the sealing agent and close the hole, because the sealing agent in the form of a liquid flows into the liquid crystal layer, and the heat applied for solidification of the sealing agent causes degradation or decomposition of the liquid crystal if the liquid crystal is applied beforehand. Therefore, liquid crystal display panels have required a complicated process for their manufacture, and have never been expected to lend themselves to continuous mass-production.
Although it appears possible to employ a transparent plastic film for a substrate for a liquid crystal panel instead of inorganic glass, there has hitherto been no example in which a transparent plastic film is used for the substrate of a field-effect display panel employing a nematic liquid crystal, because such a substrate is required to have a high level of electrical, optical and chemical properties. However, a transparent plastic film having properties which make it suitable for the substrate of a liquid crystal panel has recently become available. This invention is based on the results of the research for the sealing agent which is applicable for the manufacture of a liquid crystal panel using such a transparent plastic film.
It is a principal object of this invention to provide a liquid crystal panel having no hole for liquid crystal injection inexpensively by way of mass production using an organic panel substrate. It is another object of this invention to provide liquid crystal panels having a constantly high quality inexpensively by way of mass production. Other objects of this invention are believed to be easily understood from the following description, and not mentioned herein.